The enzymatic studies and some experiments with intact cells have been made on the biosynthetic pathway of L-ornithine in Micrococcus glutamicus. The pathway thus revealed is as follows: N-Acetylglutamic acid, which is probably formed via glutamic acid, is phosphorylated and reduced to form N-acetylglutamic-γ-semialdehyde. N-Acetylornithine is produced as the result of transamination between N-acetylglutamic-γ-semialdehyde and glutamic acid, and it is then deacetylated by the transfer of its acetyl group to glutamic acid, forming ornithine. The last-mentioned reaction seemed to be catalized by a new transacetylase. The conceivable relationship between these results and the efficient production of ornithine in the mutant of M. glutamicus has been discussed.
The Microbiology Research Foundation